Radios typically have several control knobs, buttons, or switches that enable a radio user to change or vary one or more operational parameters of the radio. Common examples of variable operation parameters include audio volume adjustments, squelch settings, and frequency selection. Possibly less well known, but nevertheless operationally significant, many radios enable an operator to change the radio's identification code, group affiliation, encryption key, or other such parameters essential to the proper operation of contemporary radios.
Generally, the control knobs, buttons and switches used in contemporary radios comprise electromechanical devices each of which must be electrically coupled (usually soldered) to a printed circuit (PC) board or circuit carrying substrate. Due to the mechanical contacts, such electromechanical control arrangements are unreliable and may fail after prolonged exposure to dust, humidity, or temperature. Since consumers demand every increasing levels of reliability, a superior control arrangement for a radio is needed.